Steel cable connector swaging method and machine thereof

ABSTRACT

A method and machine for swaging steel cable connectors are provided. The swaging machine has an external and an internal trough. The connector having a circular cross-sectional shape is first swaged in the external trough into having an oval cross-sectional shape. The connector is then moved into the internal trough, where the connector is swaged and steel cable is fixedly clipped inside the connector. With this swaging machine, replacing molds is not required and a single mold is applicable to connectors of various sizes, so that both the production time and cost are reduced. In addition, the connector after swaging would have a smooth surface so that its outlook and safe usage are both enhanced.

BACKGROUND OF THE INVENTION

(a) Technical Field of the Invention

The present invention generally relates to steel cables, and moreparticularly to a method and machine for swaging steel cable connectors.

(b) Description of the Prior Art

Connectors are often used to make steel cables into a noose or toconnect them into a longer length. The connectors are usually swaged soas to clip the ends of steel cables tightly together by a swagingmachine. As shown in FIG. 1, the connector 2 usually has a cylindricalshape. The steel cable 1 is usually made by twisting two or more steelwires into having a generally circular cross-section. In order to slipthe steel cable 1 into the connector 2, the central hole 21 is also around hole. A round central hole 21 is also easier to make with lowercost. After the steel cable 1 is slipped into the connector 2, theconnector 2 is swaged into having a smaller cross-sectional diameter bya swaging machine using stamping, so as to fixedly clip the steel cable1 inside the connector 2. The connector 2 would thereby have its lengthextended, as shown in FIG. 2. Conventionally, the swaging machine has amold 3 composed of an upper die 31 and a lower die 32 so that, whenclosed together, the upper and lower dies 31 and 32 form a circularthrough hole at their sides. The operation of the swaging machine is asfollows. The connector 2 having the steel cable 1 slipped through isplaced on the semi-circular trough 321 of the lower die 32. The swagingmachine is first operated to close the upper die 31 for only half of thecourse, as shown in FIG. 4. The upper die 31 is then lifted and theconnector 2 is rotated for 45 degrees, as shown in FIG. 5. The swagingmachine is again operated for a second swaging, in which the upper die31 is closed for one fourth of the course, as shown in FIG. 6. Then theupper die 31 is lifted and the connector 2 is rotated for another 45degrees, as shown in FIG. 7. Finally, the upper die 31 is fully closedwith the lower die 32 for a complete course, as shown in FIG. 8. Theconnector 2 now remains to have a generally cylindrical shape but with asmaller cross-section diameter and a longer length, as shown in FIG. 2and as compared to FIG. 1. The connector 2 thereby tightly clips thesteel cable 1 inside.

As described above, the conventional steel cable connector swagingmethod requires three swaging operations and two connector rotations.This is a time consuming and, thereby, costly process. Especially, thethree swaging operations requires the operator to close the upper die 31for one half and one fourth of the course, which is very difficult foran operator of ordinary skill to precisely control the upper die 31'sposition. Furthermore, the conventional swaging machine is usuallyoperated manually so as to adapt to different types of swaging processand connectors. Therefore, the foregoing process could only be operatedby an experienced operator and the operator could only control the upperdie 31's course simply based on experience and naked eyes.

In addition, every time when the connector 2 is rotated and swaged andwhen the upper die 31 is closed to press against the bulge part 22 ofthe connector 2, a side force would be generated, which would verylikely to damage the mold 3 and shorten the operation life of theswaging machine. This is especially true when the connector 2 is made ofa steel material having a high hardness. Further, for connectors havinga cross-sectional diameter greater than 1⅛ inches, since the connector 2would have a shape and cross-sectional diameter exceeding the limitationof the mold 3 after the first swaging, the mold 3 has to be replacedbefore continuing the second swaging. The replacement of mold not onlyfurther extends the operation time, increases the production cost, butalso leads to a lower yield rate.

Besides, for the two swaging operations after the connector 2 isrotated, as shown in FIGS. 4 and 6, since the connector 2 is alreadydeformed, the upper die 31's pressing against the bulge part 22 wouldleave dents on and cause a rough surface of the connector 2. Thehandsome outlook of the steel cable product is thereby comprised, andthe rough surface also often gives the operator and user cutting wounds.The conventional approach therefore presents a hazard to the safety ofthe operators and users.

To simplify the swaging process, as shown in FIG. 9, another swagingmethod is developed. This method adopts a mold 4 whose upper and lowerdies 41 and 42, when closed together, form a through hole having anearly hexagonal cross-sectional shape at their sides. The troughs onthe upper and lower dies 41 and 42 have curved surfaces 413 and 423, andplanar surfaces 412 and 422 respectively. When the connector 2 is placedon the lower die 42's trough, the upper die 41 is closed completely withthe lower die 41 so that the connector 2 would have a tube shape with acurved hexagonal cross-section, as shown in FIG. 10. The connector 2 isthen rotated for 45 degrees, as shown in FIG. 11. The upper die 41 isclosed completely again for a second swaging, as shown in FIG. 12. Theconnector 2 now has a tube shape with a hexagonal cross-section. Themethod requires only two swaging operations, and both the productiontime and cost are reduced. In addition, since the dies are closelycompletely and there is no need to estimate the course advance,operators with limited experience are capable of performing the stagingoperations.

However, the rotation of connector 2 is still required after the firstswaging operation. On the other hand, when performing the secondswaging, as shown in FIG. 11, the two planar surfaces 411 and 421 of theupper and lower dies 41 and 42 respectively are pressed against thecurved surfaces of the connector 2, a significant side force would begenerated which, similar to the previous approach, would damage the moldand swaging machine, and reduce their operation lives. As the connector2 has to be rotated for 45 degrees before the second swaging, the methodis applicable to connectors having a diameter between ¼ and 1¾ inches.Larger connectors still have to rely on the previous swaging method.Also because of the connector 2 has to be rotated, the connector 2 wouldsuffer dents and a rough surface as well, which are threats to thesafety of the operators and users. Besides the foregoing approaches,there are other swaging methods being developed but all with variouslimitations on the size of the connectors.

SUMMARY OF THE INVENTION

The primary purpose of the present invention is to provide a swagingmethod and a swaging machine which has an external through hole and aninternal through hole in the mold so that a connector could undergo twostages of swaging operations, all within the same mold for a speedyswaging process.

Another objective of the present invention is to provide a swagingmethod and a swaging machine so that connectors of various sizes couldbe swaged within a same mold, and production time and cost could therebybe saved.

Still another objective of the present invention is to provide a swagingmethod and a swaging machine so that the connectors would have smoothsurfaces after being swaged, and the connectors' outlook and safe usageare enhanced.

A further objective of the present invention is to provide a swagingmethod and a swaging machine so that no side force would be generatedduring the swaging operations, and the mold and the swaging machinecould be free from the damage of side force and would have longeroperation lives.

The foregoing object and summary provide only a brief introduction tothe present invention. To fully appreciate these and other objects ofthe present invention as well as the invention itself, all of which willbecome apparent to those skilled in the art, the following detaileddescription of the invention and the claims should be read inconjunction with the accompanying drawings. Throughout the specificationand drawings identical reference numerals refer to identical or similarparts.

Many other advantages and features of the present invention will becomemanifest to those versed in the art upon making reference to thedetailed description and the accompanying sheets of drawings in which apreferred structural embodiment incorporating the principles of thepresent invention is shown by way of illustrative example.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective schematic view of a steel cable connector.

FIG. 2 is a perspective schematic view of a swaged steel cableconnector.

FIGS. 3˜8 are schematic cross-sectional views showing the various stagesof a conventional swaging method.

FIGS. 9˜12 are schematic cross-sectional views showing the variousstages of another conventional swaging method.

FIG. 13 is a schematic cross-sectional view of a mold according to thepresent invention.

FIGS. 14˜16 are schematic cross-sectional views showing the variousstages of the swaging method according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following descriptions are of exemplary embodiments only, and arenot intended to limit the scope, applicability or configuration of theinvention in any way. Rather, the following description provides aconvenient illustration for implementing exemplary embodiments of theinvention. Various changes to the described embodiments may be made inthe function and arrangement of the elements described without departingfrom the scope of the invention as set forth in the appended claims.

In the following, detailed description along with the accompanieddrawings is given to better explain preferred embodiments of the presentinvention.

Please refer to FIG. 13. As shown in FIG. 13, a mold 5 used in theswaging machine according to the present invention has an upper andlower dies 51 and 52, which would form rectangular external troughs 511and 521 at their sides respectively. The external troughs 511 and 521are shaped by right-angled planar surfaces 512 and 522 respectively. Theupper and lower dies 51 and 52 also have semi-circular internal troughs513 and 523 respectively, which would form a through hole in the middleof the mold 5 when the upper and lower dies 51 and 52 are closedtogether.

The swaging machine according to the present invention is operated asfollows. First, the connector 2 is placed between the external troughs511 and 521, as shown in FIG. 14. The upper and the lower dies 51 and 52are closed completely to press the connector 2 into having an ovalcross-sectional shape. The connector 2 is then moved into the internaltroughs 513 and 523, as shown in FIG. 15. The upper and lower dies 51and 52 are again closed completely together to press the connector 2into having a circular cross-sectional shape and a longer length, asshown in FIG. 16. The swaging process of the steel cable connector 2 iscompleted.

According to the foregoing description, the present invention requiresonly two swaging operations, and the production time and cost are bothreduced accordingly. In addition, an operator with limited experiencecould perform the swaging operations as the operator is not required tomake precise estimation of the pressing course's advance. Further, thereis no need to replace the mold 5 since connectors of variouscross-sectional diameters could be swaged in the external and internaltroughs of a single mold. In other words, the present invention poses nolimitation on the size of the connectors. As the external troughs arelocated at the sides of the upper and lower dies 51 and 52, theconnector 2 with a steel cable slipped through is very convenient towork on. Also, during the swaging operations, the connector 2 is eitherhaving a circular or having an oval cross-sectional shape, no side forcewould be generated during the swaging operations to damage the mold 5and the swaging machine. Moreover, the swaged connector 2 has a smoothsurface without any dent. The swaged connector 2 therefore has ahandsome outlook and presents no threat to the safety of the operators.

It will be understood that each of the elements described above, or twoor more together may also find a useful application in other types ofmethods differing from the type described above.

While certain novel features of this invention have been shown anddescribed and are pointed out in the annexed claim, it is not intendedto be limited to the details above, since it will be understood thatvarious omissions, modifications, substitutions and changes in the formsand details of the device illustrated and in its operation can be madeby those skilled in the art without departing in any way from the spiritof the present invention.

1. A steel cable connector swaging method comprising the steps of:swaging a connector into having an oval cross-sectional shape within afirst trough shaped by planar surfaces of a mold; and swaging saidconnector into having a circular cross-sectional shape within a secondtrough have a circular cross-sectional shape of said mold.
 2. A steelcable connector swaging machine comprising a mold, said mold furthercomprising an upper die and a lower die, said upper and lower diesforming a first tough shaped by planar surfaces of said upper and lowerdies, said upper and lower dies forming a second trough shaped by curvedsurfaces of said upper and lower dies.
 3. The swaging machine accordingto claim 2, wherein said first trough is located at and open to a sideof said upper and lower dies.